All Questions

182
votes
7answers
284304 views

SQL JOIN and different types of JOINs

I have been going through many threads on SO and some other forums. So I thought I would summarize "What is SQL JOIN?" and "What are different types of SQL JOINs?".
126
votes
7answers
87631 views

NoSql vs Relational database

Recently NoSQL has gained immense popularity. What are the advantages of NoSQL over traditional RDBMS?
-3
votes
1answers
130 views

Normalization in database management system

I have a relation in a database: Emp_project(SSN,PNum,Hours,Ename,PName,Plocs) I have been asked to normalize the relation Emp_project. How do I normalize it?
120
votes
15answers
73419 views

When/Why to use Cascading in SQL Server?

When setting up foreign keys in SQL Server, under what circumstances should you have it cascade on delete or update, and what is the reasoning behind it? This probably applies to other databases as w...
13
votes
6answers
20468 views

TRIGGERs that cause INSERTs to fail? Possible?

In cleaning up this answer I learnt a bit about TRIGGERs and stored procedures in MySQL, but was stunned that, while BEFORE INSERT and BEFORE UPDATE triggers could modify data, they seemingly couldn't...
236
votes
10answers
85456 views

Relational Database Design Patterns?

Design patterns are usually related to object oriented design. Are there design patterns for creating and programming relational databases? Many problems surely must have reusable solutions. Examples...
68
votes
9answers
99567 views

Drop all tables command

What is the command to drop all tables in SQLite? Similarly I'd like to drop all indexes.
26
votes
7answers
6861 views

Why don't DBMS's support ASSERTION

So I recently learned about ASSERTION in my databases course, and my prof noted that major databases don't support it, even though it is in the SQL-92 standard. I tried googling to find out why, but ...
16
votes
1answers
13258 views

RMySQL dbWriteTable with field.types

I have a data frame, called df, that looks like this: dte, val 2012-01-01, 23.2323 2012-01-02, 34.343 The type on the columns is date and numeric. I would like to write this to a MySQL database us...
18
votes
4answers
20712 views

Update specific field on SOLR index

I want to using solr for search on articles I have 3 table: Group (id , group name) ArticleBase (id, groupId, some other field) Article(id, articleBaseId, title, date, ...) in solr schema.xml ...

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